Synthetic polymers Terpolymer

Just as it is not necessary for polymer chains to be linear, it is also not necessary for all repeat units to be the same. We have already mentioned molecules like proteins where a wide variety of different repeat units are present. Among synthetic polymers, those in which a single kind of repeat unit are involved are called homopolymers, and those containing more than one kind of repeat unit are copolymers. Note that these definitions are based on the repeat unit, not the monomer. An ordinary polyester is not a copolymer, even though two different monomers, acids and alcohols, are its monomers. By contrast, copolymers result when different monomers bond together in the same way to produce a chain in which each kind of monomer retains its respective substituents in the polymer molecule. The unmodified term copolymer is generally used to designate the case where two different repeat units are involved. Where three kinds of repeat units are present, the system is called a terpolymer where there are more than three, the system is called a multicomponent copolymer. The copolymers we discuss in this book will be primarily two-component molecules. We shall discuss copolymers in Chap. 7, so the present remarks are simply for purposes of orientation. 

Orientations in elongated mbbers are sometimes regular to the extent that there is local crystallization of individual chain segments (e.g., in natural rubber). X-ray diffraction patterns of such samples are very similar to those obtained from stretched fibers. The following synthetic polymers are of technical relevance as mbbers poly(acrylic ester)s, polybutadienes, polyisoprenes, polychloroprenes, butadiene/styrene copolymers, styrene/butadiene/styrene tri-block-copolymers (also hydrogenated), butadiene/acrylonitrile copolymers (also hydrogenated), ethylene/propylene co- and terpolymers (with non-conjugated dienes (e.g., ethylidene norbomene)), ethylene/vinyl acetate copolymers, ethyl-ene/methacrylic acid copolymers (ionomers), polyisobutylene (and copolymers with isoprene), chlorinated polyethylenes, chlorosulfonated polyethylenes, polyurethanes, silicones, poly(fluoro alkylene)s, poly(alkylene sulfide)s. 

The simplest polymers are those in which all of the structural repeat units (which are closely related to the structure of the monomer) are identical. Such materials are known as homopolymers. Polymers containing two or more chemically different types of structural unit in the chain are known as copolymers. The majority of these only contain two types of structural unit and are termed binary copolymers. Copolymers containing three structural units are also known and are designated ternary copolymers (or terpolymers). Synthetic polymers seldom contain more than three structural units although in nature polymers such as the proteins may contain twenty or more structural units. Whilst the following discussion is illustrated by reference to binary copolymers similar arguments may be applied to ternary and other copolymer systems. 

Occasionally polymers are used to increase the viscosity of oil-base and synthetic-base muds. The polymers for this use are typically sulfonated polystyrenes or ethylene—propylene terpolymers (EPDM) (54,55). Such polymers are usually used in conjunction with an organopbilic clay. 

Natural Rubber and Synthetic Polyisoprene Polybutadiene and Its Copolymers Polyisobutylene and Its Copolymers Ethylene-Propylene Copolymers and Terpolymers Polychloroprene Silicone Elastomers Fluorocarbon Elastomers Fluorosilicone Elastomers Electron Beam Processing of Liquid Systems Grafting and Other Polymer Modifications... 

Butadiene is a colorless, odorless, flammable gas, with a boiling point of -4.7°C and is used for the manufacture of polybutadiene, nitrile rubber, chloroprene, and various other polymers. An important synthetic elastomer is styrene-butadiene rubber (SBR) in the automobile tire industry. Specialty elastomers are polychloroprene and nitrile rubber, and an important plastic is acrylonitrile/butadiene/styrene (ABS) terpolymer. Butadiene is made into adiponitrile, which is converted into hexamethylenediamine (HMDA), one of the monomers for nylon. 

Polymer nanostrings consisting of block terpolymers of butadiene, styrene, and divinyl-benzene having a Mn of 46,744 daltons were prepared Wang [3] and used as additives in natural and synthetic automotive tires. The nano strings were then postmodified to enhance tire surface and bulk performance. 

Recently, Perro et al. [55] reviewed the developments in the field of Janus particles over the last 15 years, describing various strategies to obtain Janus-type particles using polymer precursors. One strategy is based on the self-assembly of ABC terpolymers in bulk [56, 57] or in solution [58], Another uses the electrostatic interactions of AB and CD diblock copolymers, which lead to inter-polyelectrolyte complexes [59], A different synthetic concept is to obtain Janus particles made of inorganic materials, e.g., acorn-like particles made of PdSx-CogSg [60] or... 

The nature of hydrophobic interactions and their effects on the structure and properties of water have been extensively studied, particularly for small molecules (i 3). In contrast, the introduction of hydrophobic associations into synthetic water-soluble polymers to control solution rheology has received rather limited and recent study (4-7). To better understand the relationships between polymer structure and solution properties, we have synthesized and characterized a series of copolymers of acrylamide and N-substituted alkylacrylamides and terpolymers containing anionically charged carboxyl groups. Solution properties of these systems have been obtained in both the dilute and semidilute concentration regime, to probe the influence of intra- and intermolecular interactions. In addition, the influence of the shear field and solvent quality on the associations was studied. 

Styrene serves as the monomer for the well-known polymer—polystyrene. It also serves as the source of many copolymers, that is polymers made from two monomers at varying compositions, such as SAN = styrene-acrylonitrile SBR = styrene-butadiene rubber (the major synthetic rubber) SBS = styrene-butadiene-styrene (a modem family of thermoplastic mbbers which are not cross-linked) and the well-known terpolymer ABS which is based on 3 monomers—acrylonitrile-butadiene-styrene. 

Polymer, synthetic n. The product of a polymerization reaction whose starting materials are one or more monomers. When a single monomer is used, the product is called a homopolymer, monopolymer, or simply a polymer. When two monomers are polymerized simultaneously one obtains a co-polymer. The term terpolymer is used for the polymerization product of three monomers. However, the term heteropolymer is also used for terpolymers as well as for products of more than three monomers. When no monomer is used, the product is known as a nonomer. The terms polymer, resin, high polymer, macro-molecular material, and plastic are often used interchangeably, although plastic also refers to compounds containing major additives. Note— The definition approved... 

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